Abstract: PO1619
Porcine Desiccated Thyroid Extract Associated Dual Positive ANCA Vasculitis
Session Information
- Glomerular Diseases: Clinicopathological Features and Outcomes in IgAN, Lupus Nephritis, and Vasculitis
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Kapa, Nandakishor, University of California Davis Medical Center, Sacramento, California, United States
- Madan, Niti, University of California Davis Medical Center, Sacramento, California, United States
- Cheng, Mingyu, University of California Davis Medical Center, Sacramento, California, United States
- Wiegley, Nasim, University of California Davis Medical Center, Sacramento, California, United States
Introduction
Among medications used for thyroid disorders associated with small vessel vasculitis, the most well-known is propylthiouracil. However, there have been no reported cases of ANCA-associated vasculitis (AAV) with desiccated thyroid replacement hormones. We report the first case of drug-induced ANCA vasculitis presumed to be associated with porcine desiccated thyroid supplementation (Armour Thyroid).
Case Description
A 43-year-old Caucasian woman with Hashimoto's thyroiditis and bipolar disorder presenting with 1 month of generalized fatigue, subjective fevers, and foamy urine was found to have acute kidney injury with creatinine (Cr) peaking at 3.80 mg/dL from baseline 1.0 mg/dL. She recently started desiccated thyroid supplementation prior to the onset of symptoms. Urinalysis revealed active sediment with hematuria and subnephrotic proteinuria with 24-hour urine protein 1.1 gm/day. Serologic testing was notable for MPO Ab IgG positive >8.0 AI and PR3 Ab IgG positive > 6.4 AI. Further serologic workup, including anti-histone Ab, was negative. Kidney biopsy revealed features consistent with pauci-immune glomerulonephritis with cellular and fibrocellular crescents, mild interstitial inflammation and tubulitis, and mild arteriosclerosis and hyaline arteriosclerosis. She was not taking any other known medications associated with drug-induced vasculitis. She received pulse dose steroids with taper per the PEXIVAS trial protocol and Rituximab therapy per the RAVE trial protocol. Cr improved (1.6 mg/dL) after induction therapy with persistent mild proteinuria at <500 mg/g at 6 months. Dual MPO and PR3 positivity persisted until Rituximab completion, after which only MPO positivity continued.
Discussion
It is well known that anti-thyroid medications can cause drug-induced AAV. However, this renal limited AAV case with desiccated thyroid supplementation suggests clinicians should also be aware of AAV as a possible adverse consequence of thyroid supplementation. Management should include discontinuation of the offending agent and consideration of immunosuppression with standard induction regimens based on disease severity.